From: Keir Fraser <keir.fraser@citrix.com>
Date: Mon, 23 Nov 2009 07:14:33 +0000 (+0000)
Subject: pcifront: fix multiple initialization bug
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=3a1eed210ab04da6bcc129796dadf7988f9fe9d8;p=people%2Fliuw%2Flibxenctrl-split%2Fmini-os.git

pcifront: fix multiple initialization bug

Now that we have pcifront_watches to dynamically initialize pcifront
we don't need a call to init_pcifront in pcilib and pcifront_scan
anymore; we should just wait for the frontend to connect to the
backend instead.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---

diff --git a/pcifront.c b/pcifront.c
index ed402a8..718abf1 100644
--- a/pcifront.c
+++ b/pcifront.c
@@ -276,15 +276,24 @@ void pcifront_scan(struct pcifront_dev *dev, void (*func)(unsigned int domain, u
 {
     char *path;
     int i, n, len;
-    char *s, *msg;
+    char *s, *msg = NULL, *err = NULL;
     unsigned int domain, bus, slot, fun;
 
     if (!dev)
         dev = pcidev;
-    if (!dev)
-        dev = init_pcifront(NULL);
-    if (!dev)
-        return;
+    if (!dev) {
+        xenbus_event_queue events = NULL;
+        char *fe_state = "device/pci/0/state";
+        xenbus_watch_path_token(XBT_NIL, fe_state, fe_state, &events);
+        while ((err = xenbus_read(XBT_NIL, fe_state, &msg)) != NULL || msg[0] != '4') {
+            free(msg);
+            free(err);
+            printk("pcifront_scan: waiting for pcifront to become ready\n");
+            xenbus_wait_for_watch(&events);
+        }
+        xenbus_unwatch_path_token(XBT_NIL, fe_state, fe_state);
+        dev = pcidev;
+    }
 
     len = strlen(dev->backend) + 1 + 5 + 10 + 1;
     path = (char *) malloc(len);